J/ApJ/928/152 Temporal analysis of GRB precursors in Swift-BAT cat. (Li+, 2022)
Temporal analysis of GRB precursors in the third Swift-BAT catalog.
Li L., Mao J.
<Astrophys. J., 928, 152 (2022)>
=2022ApJ...928..152L 2022ApJ...928..152L
ADC_Keywords: GRB; Redshifts; Photometry
Keywords: Gamma-ray bursts
Abstract:
We select 52 long gamma-ray bursts (GRBs) that have precursor activity
in the third Swift-BAT catalog. Each episode shown in both the
precursors and the main bursts is fitted by the Norris function. We
systematically analyze the temporal properties for both the precursors
and the main bursts. We do not find any significant difference between
the temporal profile of the precursor and that of the main burst. The
photon count of the precursor is related to that of the main burst. It
is indicated that the precursor and the main burst might have the same
physical origin, as the precursor and the main burst follow the same
τp-ω relation. However, we do not find the explicit relation
between the energy release of the precursor and the quiescent time.
Some theoretical models, such as the fallback collapsar scenario and
the jet-cocoon scenario, may be helpful to explain the GRB-precursor
phenomena.
Description:
We select the GRBs triggered by Swift-BAT in the energy range of
15-150keV from the third Swift-BAT catalog (Lien+ 2016, J/ApJ/829/7).
We then search for the precursors in the GRB lightcurves and
systematically investigate the temporal properties of the GRB
precursors. Each lightcurve has been built in five energy channels,
which are 15-25, 25-50, 50-100, 100-350, and 15-350keV. In this paper,
we use the lightcurves in the energy band of 15-350keV.
See Section 2.2.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 142 227 The fitting parameters of the GRB episodes
table3.dat 70 52 The quiescent time and the peak time
lcs/* . 52 Individual lightcurve in JPG format
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See also:
J/ApJS/175/179 : The BAT1 gamma-ray burst catalog (Sakamoto+, 2008)
J/MNRAS/448/2624 : List of isolated emission episodes in GRB (Charisi+, 2015)
J/ApJ/829/7 : 3rd Swift/BAT GRB catalog (past ∼11yrs) (BAT3) (Lien+, 2016)
J/ApJ/866/97 : Swift X-ray flash & rich GRBs in BAT3 (Bi+, 2018)
J/ApJ/862/155 : Two-episode prompt emission of GRB with Fermi (Lan+, 2018)
J/ApJ/884/59 : GRB X-ray flare temporal & spectral properties (Liu+, 2019)
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1- 7 A7 --- GRB GRB name (YYMMDDA)
9- 13 A5 --- Type GRB type
15 A1 --- l_z Limit flag on z (1)
16- 21 F6.4 --- z [0.54/6.32] Redshift (1)
22 A1 --- u_z [?] Uncertainty flag on z
24- 29 F6.2 s T90 [7/810.5] Swift/BAT catalog T90 duration
31- 32 A2 --- Peak Pulse type (2)
34- 37 F4.2 --- A [0.02/4.6] Maximum intensity in units of
counts/s/Detector
39- 42 F4.2 --- e_A [0/0.15] The 1σ uncertainty in A
44- 50 F7.2 s ts [-233/644] Start time
52- 56 F5.2 s e_ts [0.02/17.2] The 1σ uncertainty in ts
58- 63 F6.2 s tau1 [0.02/648] The τ1 parameter
65- 69 F5.2 s e_tau1 [0.02/64] The 1σ uncertainty in tau1
71- 75 F5.2 s tau2 [0.3/36.1] The τ2 parameter
77- 80 F4.2 s e_tau2 [0.01/7] The 1σ uncertainty in tau2
82- 86 F5.2 s tp [0.18/46] Peak time
88- 92 F5.2 s e_tp [0.02/15] The 1σ uncertainty in tp
94- 98 F5.2 s omega [0.8/49] Pulse width
100-104 F5.2 s e_omega [0.05/25] The 1σ uncertainty in omega
106-109 F4.2 --- kappa [0.1/1] Pulse asymmetry
111-114 F4.2 --- e_kappa [0/0.5] The 1σ uncertainty in kappa
116-120 F5.2 s taur [0.16/17.5] Rise time
122-125 F4.2 s e_taur [0.01/7] The 1σ uncertainty in taur
127-131 F5.2 s taud [0.58/39] Decline time
133-138 F6.3 s e_taud [0.03/12.1] The 1σ uncertainty in taud
140-142 A3 --- Ref Reference of previous GRB precursor identifier (3)
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Note (1): All redshifts are spectroscopic except for the ones with limits.
Note (2): Pulse type as follows:
p = precursor (77 occurrences)
p1 = (11 occurrences)
p2 = (11 occurrences)
p3 = (1 occurrence)
m = main pulse (127 occurrences)
Note (3): Reference as follows:
B08 = Burlon et al. 2008ApJ...685L..19B 2008ApJ...685L..19B
H14 = Hu et al. 2014ApJ...789..145H 2014ApJ...789..145H
L18 = Lan et al. 2018, J/ApJ/862/155
C20 = Coppin et al. 2020PhRvD.102j3014C 2020PhRvD.102j3014C
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Byte-by-byte Description of file: table3.dat
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Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 7 A7 --- GRB GRB name (YYMMDDA)
9- 13 A5 --- Type GRB type (1)
15- 20 F6.4 --- z [0.5/6.4] Redshift
22- 27 F6.2 s T90 [7/810.5] Duration T90
29- 34 F6.2 s delTq1 [2.8/527] Quiescent time, Δtq,1
36- 41 F6.2 s delTq2 [5.8/101]? Quiescent time, Δtq,2
43- 47 F5.2 s delTq3 [41.6]? Quiescent time, Δtq,3
49- 54 F6.2 s delTp1 [7.8/636] Time between the peak time of one
pulse to the peak time of the subsequent pulse,
Δtp,1
56- 61 F6.2 s delTp2 [12.8/140]? Time between the peak time of one
pulse to the peak time of the subsequent pulse,
Δtp,2
63- 67 F5.2 s delTp3 [58.16]? Time between the peak time of one
pulse to the peak time of the subsequent pulse,
Δtp,3
69-70 I2 --- Fig [1/52] Figure subset number in Figure 18;
column added by CDS
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Note (1): GRB type as follows:
XRR = X-ray rich (32 occurrences)
C-GRB = classical GRB (20 occurrences)
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History:
From electronic version of the journal
(End) Prepared by [AAS], Emmanuelle Perret [CDS] 01-Mar-2024